Iron core in electricity meters



Oct. 19,1926.

J. ZUGEH IRON CORE IN ELECTRICITY METER Filed May 26, 1924 Inventor Patented Oct. 19, 1926. 1

UNITED STATES PATENT OFFICE.

JULIUS ZUGER, 0F ZUG, SWITZERLAND, ASSIGNOR 'IO LANDIS & G-YR S. A., OF ZUG,

SWITZERLAND, A SWISS IRON CORE IN ELECTRICITY METERS.

Application filed May 26, 1924, Serial No. 715,962, and in Switzerland June 22, 1923.

In order to reduce the magnetic resistance to the main current flux in electricity meters, a ferro-magnetic shunt path has been provided in certain shapes of core on the opposite side of the disc to the current coil. By this means a considerable increase in torque was obtained. In order to prevent a large percentage of the eifective pressure flux from flowing along this shunt path which may be in the form of a pivoted bridge piece the said bridge piece has been secured by brass bolts at some distance from the pressure core. Now experience has shown that this arrangement has the disadvantage that it causes considerable distortion of the error curve at low loads.

In electricity meters it is desirable to keep this curve as flat as possible, as the same then does not appreciably influence the reading of the meter.

This object is obtained by the present invention, according to which a lateral extension is mounted on either side of that part of the pressure core facing the driving disc. The invention is applicable to various shapes of core employed for electricity meters.

The drawing shows a perspective view of an example of the subject of the invention, Fig. 1 showing a view of the whole iron core, and Fig. 2 the parts forming the lateral extension mentioned above.

In the drawing 1 represents the pressure core, 2 the current core and 3 the driving disc of an electricity meter.

On the section of the pressure core facing the driving disc 3 is mounted a lateral extension consisting of two iron blocks 4 mounted one on either side of the core. The blocks 4: are laminated and are mounted on a bolt- 5 which passes through a hole in the pressure core 1. This bolt 5 has two diametrically opposed flattened sides 6. Each of the small iron blocks has a hole, the section of which corresponds to the profile of the bolt 5. Hence the iron blocks are firmly held against turning on the bolt 5.

The purpose of the iron blocks 4; is to enlarge the effective magnetic flux and to produce thereby an increase in the torque and to produce a very strong flattening 011 the curve which indicates the error. These properties are attained primarily by making the enlarging parts of adjustable laminated blocks of iron. By making them of single sheets, the production of eddy currents is prevented and the magnetic fluxes are made more eiiicient. Particularly the tensional fluxes are increased. This is due to the condition that the lines of force emanating from the main current magnets must pass through the laminated blocks of iron in a direction transverse to the laminae. This of course produces a reluctance to the lines of force, but this reluctance is still far less than if the lines of force would have to flow through air exclusively. By adjusting the laminated blocks of iron, the torque of the driving disc can be regulated and increased.

By making the small iron blocks 4 ad justable, as in the example of construction described, it is also possible simultaneously to regulate the torque.

vVhat I wish to secure by U. S. Letters Patent is: 1

1. An iron core for an electrical meter, having a lateral extension on either side, each extension comprising a laminated iron block, adjustably mounted on the pressure core.

2. An iron core for an electrical meter, having a lateral extension on either side each extension comprising a laminated iron block adjustably mounted on the pressure core, and a bolt extending through said core and said laminated blocks.

3. An iron core for an electrical meter, having a lateral extension on either side,- each extension comprising a laminated iron block adjustably mounted on the pressure core anda bolt extending through said core and said laminated blocks, said bolt being free to turn in said core and said lglgcks being secured against turning on said In testimony whereof I aflix my signa ture.

JULIUS ZUGER. 

